The Lego Block Exercise

Noah Weiss
Published in
7 min readDec 1, 2014


What drove Foursquare to split into 2 apps

By Noah Weiss, VP Product at Foursquare

A year ago, with Thanksgiving fast approaching, we started thinking about what were the big areas Foursquare could invest in for 2014. It seemed obvious: make checking in faster, improve search quality, make the venue page more authoritative, and so on. It was a reasonable plan. It was an uninspired plan.

So we started over. We listed out all our assumptions about the constraints we had:

  1. A hybrid privacy model: Foursquare supported symmetric friendships, because check-ins are sensitive location data. It also had a public follow model, since tips are about broadcasting your expertise.
  2. Two overlapping content types: check-ins are ephemeral, tips are evergreen, yet they both tie text and photos to a place.
  3. A location sharing brand: that seemed inextricably tied to our search product, even though many people who said they wanted personalized recommendations had no interest in sharing their location with friends.
  4. Personalization fueled by check-ins: that’s the flywheel that improves the experience the more you use the product, yet our ability to passively snap people to places was getting significantly better every day.
  5. A single app: it seemed like there was no way to break this one.

Then we threw all the constraints away, laid out the great assets we had to work with, and imagined from scratch what world we would build if we started anew.

This post is about how we set up the Lego Block Exercise, and why you should do it for your company, too.

Clear off the table

Start off laying out what beliefs your company holds most precious. The dogma that boxes in most discussions, as if those beliefs were rules of nature. Here are some examples prominent tech companies face today:

  • Twitter: the feed is fueled by people you explicitly follow.
  • Uber: we transport people from point A to point B.
  • AirBnB: the guest experience is controlled by our hosts; we’re just a marketplace.
  • Pinterest: our product is for discovery; our publishers handle commerce.

These are the firm lines companies draw that help them focus. They are the bumper lanes management gives teams so they don’t throw the ball into the gutter.

These firm beliefs let you operate without constant existential angst. But for this exercise, enumerate them and make sure everyone knows none are sacred. A great new direction doesn’t require you throwing them all away, but you have to be willing to.

Lay out the blocks

Why do people love your company? If you break down the product, what are the critical pieces? What is the foundation the whole experience stands on? What can your company do no one else can?

These are your lego blocks. 3 is too few, and 30 is definitely too many. When we did this exercise at Foursquare, these were some of the blocks:

  • 6 billion+ check-ins: the unique data asset that fuels everything.
  • 50m+ tips: the perfect length content on mobile to answer the question, “What’s great here?”
  • Pilgrim: our background location technology, built off 6 billion+ check-ins, that can snap people to places and send magical push notifications.
  • Explore: our personalized local search engine that blends in your interests and the places people you trust love.
  • Venue database: the biggest and highest quality unencumbered database of places that has strong coverage in nearly every country on earth.

There were about a dozen more. The best way to phrase the question to find all the lego blocks was, “If you left your existing company and could take anything you wanted with you, what would give you the biggest unfair advantage versus another startup?”

Assigning homework

We did this exercise when we had around 150 people. It felt like 10 was the right number of people to invite. Any bigger and the discussions would have gotten unwieldy. We pulled together a set of people spanning product, design, server and client engineering. We encouraged them to pull in the best ideas from the rest of the company. This all happened in the open, with regular updates at company meetings, and letting anyone submit homework if they had ideas they were passionate about. The blend of support from the CEO and the bottom-up generation of ideas is a big part of what made this exercise work.

At the kick-off meeting, we gave out these exact rules:

You can use some of the lego blocks, or you can use all of them. You can invent new ones. You can dream up changes to the existing app or dream up three different apps. You can pitch “1 app and a website” or “three apps and two websites”. Feel free to seek inspiration outside of this room — there are so many smart people with great ideas here at Foursquare and I strongly encourage you to think of yourself as a “gather of great ideas” over the next 10 days.

We quickly realized it would be helpful to provide guidelines for what a great proposal would look like. It made sure every team addressed the hardest questions we needed to answer before picking a direction.

The pitch: what’s the 1-line tagline for your service? How would a friend tell another friend to download it at a bar? If someone asked, “How is this different from…”, what would you say? What people are you building for and what problems of theirs are you solving?

The product experience: what you would actually build, what are the key features, how do they connect. Anything from sketches to wireframes to visual designs to prototypes can be useful here.

The rationale: why are you confident this strategy will work? Piece together user research, our own data, external data, competitors, and a coherent argument.

The plan: if we started working on this the week after Thanksgiving, what order loosely would we build things? How could we quickly validate assumptions and test hypotheses? How would you roll it out? A user acquisition plan matters.

You could reuse this exact assignment, since it intentionally had very little specific to Foursquare.

A surprising consensus

We wanted the ten people to go off in divergent directions. Except for one checkpoint where people could merge into teams, we wanted them to not talk to each other.

It turned into one of the company’s most productive two weeks ever. People quit their day jobs, effectively. They stopped responding to emails, Asanas, and meeting invites. Everyone just started writing, and wireframing, and editing all the crap ideas out every day. Throwing out the constraints, people realized how much had held their thinking back.

I joined up with one of our engineering leads who was part of the 10, since we were 90% moving in the same direction. Two great designers joined us.

Before our roundup meeting, everyone sent out their proposals for people to digest overnight. The next day, everyone came in with the same shock: we all basically agreed. There were huge differences in people’s approaches, which it took months to hash out and take the best pieces of, but at a high-level almost everyone came to the same conclusion.

Maybe we were lucky. I have a feeling, though, that beneath most companies’ strategic plans is a set of better, bolder ideas that people would almost universally rally behind. It just takes relaxing the previously firm constraints and laying out the company’s lego blocks to get there.

For the future

The biggest benefit of the Lego Block exercise was it broke us out of the lull from the monotony of continuous progress. We had fallen into a rhythm of bi-weekly product reviews: metric X +1.2%, metric Y -0.4%, launched experiments A and B, starting design for a new feature improvement, etc. It made us feel like the machine was humming. Metrics moved! Experiments (in)validated assumptions! But to what end?

The Lego Block exercises forces your company to do painful, important thinking.

Some lessons we learned for the next time we do this:

  • Get a wide range of views: pick a mix of engineers, designers, PMs, and other roles depending on your company to see how people from different disciplines would approach the challenge.
  • Hunter-gatherer: each person is hunting for great ideas. Heavily encouraging them to gather them from across the company. It will surface more great fodder, and everyone will feel more invested.
  • Don’t sweat the details: when people reconvene, focus on the commonalities. What assumptions did everyone agree the company has to throw away? What key experiences were broken? What lego blocks were missing? Ignore all the small details, which teams will figure out once you start building.
  • Not the sum of parts: be careful of turning all the proposals into a Frankenstein. Take the best ideas, but merge them into something that is cohesive and stands on its own. This isn’t roadmap by commitee.
  • Start teams with problems: even though many of the proposals will have detailed solutions, you should give your newly staffed teams clear problems to solve and lots of leeway on coming up with answers. Resist the urge to make an uber-plan that strips away teams’ creativity.

That’s it. Get started.

Want to work at Slack — in NYC? We are hiring talented engineers, product managers, and designers. Visit to find out more, or email me directly at nweiss @ slack-corp . com.



Noah Weiss

CPO @SlackHQ . Ex @google & @foursquare . Brooklyn born, cortado lover.